Method of extracting wax



H.l M. NICHOLS. METHOD 0F EX'TBACTING WAX. APPLICATION min MAR. 7, 1919.

Patented oct. 26,1920.v A

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METHOD oF EXTRACHNG WAX.

APPLICATION FILED MAR-7, I9I9.

1,356,550. Patented Oct. 26, 1920.

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1H. M. NICHOLS.

METHOD 0F EXTRACTING WAX. APPLICATION FILED MAR. 7, 1919.

Patented Oct. 26,1920.

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H. M. NICHOLS. METHOD 0F EXTRACTING wAx. APPLICATION FILED MAR. 7, I9I9.

Patented Oct. 26, 1920.

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UNITED STATES PATENT OEmcE.

HOWARD M. NICHOLS, `OE SWARTHMORE, -PENNSYLVANIA, ASSIGNOR TO THE ATLANTIC REFINING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A.

CORPORATION OF PENNSYLVANIA.

METHOD OF Exrmc'rme WAX.'

Specification of Letters Patent.

Patented Oct. 26, 1920.

origina application med February 25, 191s', serial N. 218,994. Divided and this application med umh 7, 1919. Serial No. 281,263.

To all whom t may concern.'

a citizen of the United States, residing at Swarthmore, county of Delaware, State of Pennsylvania, have invented a new and, useful Method of Extracting Wax, of which the following is a specification.

My invention relates to a method of filtering material from a liquid, and particularly for extracting` wax, tallow or other readily fusible solids from a liquid, as oil, and more particularly for the extraction of para'flin waxfrom pa-raiin petroleum distillate.

This application is a division of my application Serial Number 218,994, filed February 25, 1.918, now Patent No. 1,302,832.

In accordance with my method, the liquid containing the material to be extracted therefrom is forced under suitable pressure into a vchamber having 4a wall consisting of a suitable filtering medium', as fabric, of small heat capacity and low heat conductivity, disposed in a surrounding atmosphere which has free and direct .access to and contact with the filtering medium throughout substantially its entire surface or area, the

material to tbe extracted collecting upon one side'of the filtering medium and the liquid filtrate passing through the filtering Inedium to the opposite side thereof into the surrounding atmosphere.

' In the case of wax, tallow or like materials the liquid, as oil, containing the same may be suitably chilled to cause the more ready .separation on the filtering medium,` and in such case" the atmosphere surrounding the filtering medium is maintained at any suitable low temperature equal to, lower or higher than the temperature of the chilled li uid operated upon.

Vhen the extracted materialis of a character which readily melts or fuses, as inthe case of wax, tallow or the like, it is preferably removed by melting it vwhile on the filtering medium and drawing it off 'in liquid form, and'thereafter solidified by coo Vhen the extracted material is wax, tallow or the like containirv" oil or similar liquid, it may be brought to a temperature suitable for sweating out the Oil or contained liquid while on the filtering medium,

and thereafter melted and drawn off therestantially entirely by a fabric or equivalent filtering medium'which has small heat capacity and lov'i7 heat conductivity and which is supported relatively free and independently of plates or -parts of metal or other lmaterial of relatively high heat conductivity and capacity and is surrounded by a free atmosphere without closely approaching parts of metal or other material Of'high heat conductivity and high heat capacity. By employment of such structure, the wax or other material is readily extracted from the Oil or other liquid, and there is effected an economy inthe energy employed for maintaining the'filtering apparatus at the necessarylow temperature because of the small amount of heat which can flow into the apparatus because of its small heat 'capacity. The heat content of the apparatus after the rise in temperature necessary for melting the wax o'r other material for its removal from the filter chamber is small, and there is correspondingly small loss upon reintroduction of chilled liquid which must again reduce the temperature of the filterapparatus.

yinvention resides in a method of the character referred to and in further features hereinafterdescribed and claimed.

For an understanding of `my method, r`eference is to be had to the Vaccompanying drawings, in which:

Figure 1 is a vertical sectional view, partly in elevation, showing a single unit of wax pressing apparatus.

Fig. 2 is a vertical sectional View, partly in elevation, taken at right angles to Fig. 1.

Fig. 3 is a horizontal sectional v1ew,.

partly in plan, through a housing or room in'which is contained a plurality of my wax pressing units.

Fig. 4 is a vertical sectional View, some parts in elevation, taken on the line 4 4 of i 3. Fig. 5 is a vertical sectional view, some .parts in elevation, taken on the line 5-5 of Fig. 3.

Fig. 6 is a. vertical sectional view, some parts in elevation, taken on the line 6-6 of 4:, Fig. 7 -is a top plan view of a` modified form of apparatus.

Fig. 8 is a side elevational view of appaf` ratus shown in Fig. 7.

Fig. 9 is a horizontal sectional view and plan of the lower part of the apparatus of f or form, though tubular form is preferred,

and for brevity the casin or chamber 1 is herein referred to as a tu e.

The tube or hose lis preferably of circular cross section, though it 'will be understood that itmay be of any other suitable cross section. It is preferably long as compared to its diameter, and as an example merely and withoutlimiting my invention to any particular dimensions, the tube'l may b'e 20 feet long, and have a diameter of 2 inches, more or less.

The tube 1 is preferably disposed in a vertical position with its upper and lower ends clamped to or otherwise suitably held in liquid tight relation with the tapered plugs or blocks 2, 2 longitudinally of which are forced the glands or clamping-members 4 by taking up upon the bolts 3. The end of the tube 1 is confined between themembers 2 and 4, and as the member -4 is drawn longitudinally of the member 2, the hose is securely clamped between them, forming a pressure-tight joint.

ln case exceptlonally high orf unusual4 pressures are employed, there may be disiposedaround andoutside of the hose 1 an ,armor 5 of metal, fabricor cord of any suitable structure having suitable openings for ypassage of liquid `therethrough; for example, a woven wire armor such 'as commonly used on air hose may be employed.

Thellower plug or block 2 has therein a passage 6 communicating with the interior of the tube 1 and connecting through pipe 7 and valve 8 with a header pipe or manifold 9 connectingwith the sourcerof wax,

bearing oil. 1

Extending longitudinally of and preferably at the centerof the tube 1 is the'pipe 10 which at itslower end isy threaded into the lower plug or block 2 in communication with the passage 11 therein, which latter at its lower end communicates Vthrough the pipe 12 and the valve 13 with the manifold or header 14 communicating with a source offjany suitable heating medium, as steam,

which is passed upwardly through the valve 13, pipe 12, passage 11 andA pipe 10 to the exhaust manifold or header 15. At its vlippernend the pipe 10 extendsthrough the ber 2, and within the hole 17 and beneath the gland 16 is .disposed the packingmaterial 18 which?, upon advance. of the gland member 16 downwardly, makes a pressuretightV connection between the pipe 10 and the block 2. By this construction expansion or contraction of pipe 10 due totemperature changes may take place without effect upon hose 1 or upper plug 2.

In the lower plug or block 2 may be provided a third passage 19, Fig. 2, communieating with the interior of the tube 1, either directly orthrough a tube 19a of any s uitablelength screw threaded .into the plug 2 and communicating with the passage 19. The passage 19 communicates through pipe 20 and valve 21 with the manifold or header 22 through whichsteam or any other suit able heating medium is delivered for pui" yposes hereinafter described.

Any suitable number 'of hose or tubularl units 1 of the character above described may be assembled in a bank as illustrated in Figs. 3, 4 and 5, within any suitable room or chamber whose side walls, bottom and roof are indicated respectively at 23, 24 and 25, all preferably of poor' heat conductivity or suitably insulated against heat .transfer therethrough.

Along one side near the bottom of the room is a pipe or header 26 and on the opposite side is a similarly disposed header or pipeA 27. 'Extending between the pipes 26 and 27 are the four groups of transverse headers or pipes, each group comprising the three pipes 9, 14 and 22 hereinbef'ore referred to, each hose unit communicating with the headers 9, 14 and 22 through the pipes and valves as described'in connection i with Figs. land 2. At the ends of the 36 and 37, the pipe 27 having in addition a I safety valve or relief valve 38 indicated in t the top of the room are disposed the horizontal pipes or headers 15 with which the pipes 10 vof the several tube units commumcate.

As illustrated in Figs. 4 and 6,-there is disposed on each of the opposite sides near the Atop of the chamber a refrigerating coil 39 through which is circulated any suitable cooling medium, as' for example, chilled brine.

' or block members 47 cast integral with the' bottom suitably inclined toward and de.

livering into the draw-off:` pipe 42.

When necessary to repair a tube unit or to discontinue its operation for any cause,-

-it may be isolated or taken out of service by closing its associated valves 8, 13 and 21. Referring yto Figs. 7 to 10 inclusive, a modified and simpler structure is shown.

At the top of the apparatus are the horizontal pipes or manifolds 43, each closed at its one end at its other connected to the pipe 44, -to which steam or other heating fluid is delivered through the valve 45. Connecting with each pipe 43 is a plurality of vertical pipes 10 extending, as in Fig. 1, throughl the gland members 16 carried by the upper plugs or blocks 2, to which the hose or tubes 1 are secured by the members 4 the pipes 10 extending to the bottom of the apparatus and into the holes 46 in the tapered plug manifold 48 havingv the longitudinally extending chambers 49 and 50, Fig. 10, the holes 46 communicating with the chamber 49 connected through valve 51 with the steam outlet pipe 52. The fabric tubes 1 are secured, as in Fig. 1, at their lower ends by members 4 to the blocks or plug members 47. With the chamber 50 in the manifold 48 communicates a hole 53 in each member 47,

and the chambers 50 at one end -communicate through the hand valves 54 with the pipe .55, controlled byhand valve 56 lfor deliveringv the wax bearing liquid into the cham- I bers 50. The pipe 55 communicates through Y the valve 57 with the pipe 58, through which melted wax may be drawn olf. Communicating with the pipe 55 is the pipe 59, controlled by the hand valve 60 and communi- .'cating with the reliefavalve 61, which communicates with the pipe `62. To the ipe 59 may be attached pressure vgage 63. With the otherv end of each of the chambers 50 is connected a pipe 54 communicating through handI valve with the pipe 66 connected with a source of air underpressure. Beneath the 'manifolds 48 is disposed a pan 41 having the oil draw-off pipe 42 controlled by valve 69. From pipe 42 there isa branch pipe connecting with pipe.58 and controlled by valve 68. I

The mode of practising my method in accordance with Figs'. 1 to 6 in extracting wax from paraffin distillate is as follows:

The valves 35 and 37 are closed andvalve 36 opened. The valves 29, 30, 32 and 33 in the transverse headers 14and 22 are closed.

remain open except when the unit is to be isolated or taken out of service. The valves 28 and 31 in thetransverse headers 9 are opened. Thereupon the valve 34 is opened, with the result that there is delivered through the pipe 26 wax bearing oil, such as thepetroleum product known as paraflin distillate, chilled to suitably low temperature, as for-example, 32 degrees F. or any suitable higher or lower temperature. The wax bearing oil is pumped through the pipe 26 under any suitable pressure and is delivered into the transverse headers 9 and from them through Athe valves `8 and pipes 7 tubes or' hose 1, completely filling them. The wax collects and is retained upon the inner walls of the fabric tubes 1 and the oil, more or less completely freed of wax', passes through the fabric walls, trickles down the outer surface thereof 'and collects in the pan 41v and is drawnv ofl' through the ipe 42 to any suitable point, asa storage tan r.

Upon first introducing wax bearing oil into a tube 1 a low pressure on the oil suffices; but as wax collects within the tube, resistance to the flow of oil progress'ivelyincreases,. requiring increasing oil pressure', which may reach 125 pounds per square inch, or higher.

Should the pressure of the wax bearing oilv delivered through the pie 26 exceed a predetermined value to which 'the relief or safety valve 38 is set, the latter will open, and allow passage of wax bearing oil through the transverse headers 9 `into the header 27 through the valve 36 and relief valve 38, and thereby prevent excessive Vpressure within the tubes 1.

While .the `wax may be pressed or eX- tracted from the waxbearing oil as above described without additional chilling of the room o r chamber, it is preferred to Ycool the chamber by passing cold brine or other medium through the coils 39, the heating coils 40 in the meantime being inoperative. The room and!v therefore the atmosphere surrounding the tubes 1, is additionally chilled,- and preferably to a-temperature several degrees below the temperature of the wax bearving oil delivered into the tubes. By so main- 'cloud test than in the case where the temperature external to the tubes 1 is not so maintained lower than the temperature of the wax bearing oil entering lthe tubes.

The delivery of wax bearing oil through the pipe 26 is continued until the tubes 1 are filled with wax, or until the deposit of wax upon the inside of the tubes has reached a desired thickness. If it is desired to sweat out the oil contained in the wax while the latter is in the position in which ,deposited in the tubes '1, the valves 34 and 36 are closed, and the valve 35 opened,'thereby admitting any suitable heating fluid through the right end of the pipe 26, Fig. 3. The valves 29 in the transverse headers 14 are opened, and heating fluid delivered therethrough and through the pipes 12 and passages 11 in the plugs or blocks 2 into the pipes 10 within the tubes 1, the heating fluid passing upwardly through these pipes and escaping into the header 15 and carried off thereby. The heating fluid flowing through the pipes 10 is regulated to impart to the-wax a suitable temperature for causing the oil contained therein to sweat out therefrom. The oil in so separating from the wax passes outwardly through the. wax and through the fabric walls of the tubes 1, trickles downwardly on the outside of the tubes, and collects in the pan 41 and is drawn off through-the pipe 42.

This sweating process may be aidedlby shutting off the flow`of chilled brine through the pipe coil 39 and passing steam or other heating medium through the lower pipe coils 40 to produce a suitable temperature within the room or chamber.

To remove the wax from the tubes 1 either in the case where the wax has first been sweated out as above described or in the case where it has not been so treated, heating fluid at sufliciently high temperature is passed in suiiicient quantity through the pipes 10 as heretofore described to raise the. wax to and above its melting point, where-v upon it flows downwardly through the pas.- sages 6 in the lower plugs 2 through the pipes 7 and valves 8 to the transverse headers9 and thence through the now open valve 31 into the header 27 and delivered through the now open valve 37 to any suitable point or to storage. Or for thel purpose of melting the wax, the valves 30 in the transverse. headers 22 are opened, whereby steam or other heating fluid flows through the valve 35 and header 26 through the valves 80 to the transverse headers 22 and thence through the pipes 20 and valves 21 through the passages 19 in the lower plugs or blocks 2 and through the short pipes 19a directly intothe interior of the tubes into direct contact with the wax, which melts and flows out through the passages 6 and pipes 7, valves 8 and transverse headers 9, through pip-e 27 and valve 37, as above described. Or eating fluid may be simultaneously passed through the pipes, 10 and -admitted through the pipes 19a for wax melting purposes.

.When the tubes 1 have been cleared of wax, the operation may be repeated byagain suitably setting the valves and admitting chilled wax bearing oil.

The practice of my method in accordance with Figs. 7 to 10 inclusive is in eneral the same as that above described. rieiy it is 'as follows:

By opening the valve 56 and the valves 54, the valves and 57 being closed, the chilled esV wax bearing oil is delivered under pressure the gage 58. Ifthe pressure rises above a l predetermined value, the relief valve 61 opens and some of the wax bearing oil will pass'ofl through pipe 62, back to the reservoir or tank containing the wax bearing oil to be treated. By such arrangement the tube 1 are protected against rupture. j

After wax has accumulated to suitable de th or thickness on the inner walls of the tu es 1, the valve 56 may be closed and the valves 45 and 51 opened, whereupon steam or other heating fluid will pass downv .irdly through the pipes 10 from the manifolds 43 into the chambers 49 of the lower manifolds 48 and through the valves 51 and out of the pipe 52. Accordingly the wax within the tubes 1 is raised in temperature to sweat out oil therefrom, which passes outwardly through the fabric tube. Or preferably, the temperature is raised to a point causing the wax to melt, whereupon it will flow downwardly through the holes -53 into the chambers 50, out through the valves 54 and 57 to the pipe 58, which, carries it to its destination, where itis solidified and may later be sweated out. Thereafter the operation may be repeated by again introducing wax bearing oil through the valves 56 and 54 as above described. y

Whenfthe wax is melted inthe tubes` 1 some escapes through themand finally collects and solidifies in the pan 41. It ma there be melted by passing steam throug the pipes67, and drawn off through pipe 42 and valve 68 to pipe 58, valve 69 being closed.

Whenever desirable, the chambers 50 may be cleared of wax bearing'oil or of melted Wax by opening the valves 65 and adm-itting air or otherl suitable medium under pressure to blow the oil or melted wax out V through valves 54, the oil being delivered back, if desired, through valve 56,`or drawn off through ipe 58; and melted wax may be blown of? through the valves 54 and pipe 58.

In accordance with my method of filter-l ing wax or the like from oil or the like, the oil or liquid is chilled to suitably low temperature to cause wax or other content to crystallize or take such form as readily to be retained by the filtervmedium, and introducing the chilled liquid, under suitably high pressure, into a filter chamber whose wall is thermally visolated and of suitable pressure withstanding fabric' o r material of low heat capacity and low heat conductivity, the opposite faces of the filter medium being in free contact, respectively, with the surrounding atmosphere, which is preferably chilled, and the liquid or oil to be filtered, the operation taking place under such conditions that substantiallyno heat conduction can take place to the liquid while undergoing filtration. The wax or other material retained upon the filter medium is thereafter melted by suitable application of heat, Aand drawn off in the melted state. Thereafter chilled wax bearing oil or like liquid may be again introduced into contact with the filter medium, under conditions of practically no absorption of heat employed in the preceding wax melting operation, whereby refrigeration is economized. v

In the oil before filtration the proportion of paraffin wax to Aoil is relatively very small as compared to the proportion of wax to oil in the material retained upon the filter fabric. The wax, collected upon the filter medium, Vis a mixture of wax and oil in approximately equal amounts. Theoil so associated with the wax is sweated out, as described, either while the wax is retained upon the filter medium or after removal therefrom.

What I claim is:

l. The method of extracting wax from liquid, as -paraf'lin wax from .paraflin distillate, which consists in forcing chilled wax bearing liquid under pressure into contact with one side of a filtering medium whose opposite side is in free and extended contact with the surrounding atmosphere, maintaining said surrounding atmosphere at a temperature lower than the tempera .l ture of the wax bearing liquid, the wax collecting upon said filter medium and the liquid passing therethrough into said surrounding atmosphere. l

2. The method of extracting fusible material from liquid, as paraffin wax paraffin distillate, which consists in forcing chilled liquid containing the material under pressure into contact with a filter medium, whereby the material collects upon said medium, and thereafter melting the said material while on said medium and drawing the'same offl in liquid form.

3. The method of extracting wax from liquid, as'paraflin lwax from paraflin distilfrom late, which consists in forcing chilled wax bearing liquid Aunder pressure into Contact with a filter medium, whereby wax collects thereon, raising the temperature of the wax while onv said medium to sweat out liquid, as oil, and thereafter removing the wax.

4. The method. of extracting wax from liquid, as paraffin wax from paraflin distil-v late,lwhicl'1 consists in forcing chilled 'wax vbearing liquid under pressure into contact the temperature of the wax, and thereafter removing /the wax from said tube.

6.- The method of extracting wax from liquid, as' paraffin wax from paraffin distillate, which consists in forcing chilled wax bearing. liquid into a fabric tube', whereby wax collects within saidl tube, passing a heating medium through said tube to raise lthe temperature of the wax to sweat out liquid, ,as oil, and thereafter melting the wax within the tube and drawing the same ofi:l therefrom in liquid form.

7. The method of extracting wax from liquid, as paraffin waxA from paraffin distillate, which consists in forcing chilled wax bearing'liquid into a fabric tube,-whereby wax collects within said tube, passing a heating medium through said tube to melt the waxl therein, and drawing ofl'the wax'collected therein.

8. The method of extracting wax from liquid, as parafiin wax from paraffin distillate, which consists in chilling the wax bearing liquid', filtering the liquid while chilled and under ressure through a pressure withstanding filter medium of low heat conductivity and capacity whose opposite sides are respectively in free and vextended contact with the surrounding atmosphere and with the wax bearing liquid, and chilling the surrounding atmosphere to a temperature lower than the temperature of the wax bearing liquid while undergoing filtration.

9. The method of extractingy wax from liquid, as paraffin wax from paraffin distilf late, which consists in chilling the Wax bear# ing liquid, filtering the liquid while chilled and under pressure through a pressure withstanding filter medium of low heat conductivity and capacity whose opposite sides are respectively in -free `and extended contact with the surrounding atmosphere and with the wax bearing liquid, and removing the wax and associated liquid from said filter iso medium by melting the wax and drawing off the melted wax and associated oil.

l0. The method of extracting paraffin wax from paraffin distillate, which consists in chilling the wax bearing oil, filtering the oil while chilled and under pressure through av pressure withstanding filter medium of low heat conductivity and capacity whose opposite sides are respectively in f ree and extended contact with the surrounding atmosphere and with the wax bearing oil,

removing the wax and' associated oil from said lter medium bymelting the wax and drawing oil the melted wax and associated oil, and thereafter separating the wax from the associated oil.

11. The method of extracting parailin wax from parain distillate, which consists in chilling the wax bearing oil, filtering the oil while chilled and under pressure through a pressure withstanding filter medium of low heat conductivity and capacity whose opposite sides are respectively in free and extended contact with the surrounding atmosphere and with the wax bearing oil, i

applying heat to the wax and associated oil held on said filter medium from the side of said lter medium on which lsaid wax and oil have accumulated, and drawing off the melted wax and the associated oil.

' 12. The method of extracting paraffin wax from paralin distillate, which consists in chilling the wax bearing oil to low temperature, forcing the chilled oil under pressure into a fabric pressure withstanding tube whose outer and inner surfaces are respectively in free and extended contact with the surrounding atmosphere and with the wax bearingoil, collecting the wax upon the inner surface of said tube, forcing the oil through the fabric wall of said tube into contact with the surrounding atmosphere, and removing the accumulated wax and associated oil by melting the wax and drawing it ofi' in liquid form with the associated oil.

In testimony -whereof I have hereunto aixed my signature this 5th day ofMarch, 1919.

' HOWARD M. NICHOLS. 

